Communications in Asteroseismology
... the first results from space asteroseismology are available? Isn’t it odd to celebrate the 65th birthday of a renowned asteroseismologist who is far from retirement at this point? The answer to the first question is easy: at the outset of this meeting, MOST was already in space and COROT was soon to b ...
... the first results from space asteroseismology are available? Isn’t it odd to celebrate the 65th birthday of a renowned asteroseismologist who is far from retirement at this point? The answer to the first question is easy: at the outset of this meeting, MOST was already in space and COROT was soon to b ...
elt science case
... most cases GRB afterglows are so faint (V ~ 23 at 1 day after the burst occurrence) that large telescopes are required to monitor their emission up to the late phase in order to observe the characteristic jet break time. At present, the most successful monitoring campaigns rely on the use of 10m–cla ...
... most cases GRB afterglows are so faint (V ~ 23 at 1 day after the burst occurrence) that large telescopes are required to monitor their emission up to the late phase in order to observe the characteristic jet break time. At present, the most successful monitoring campaigns rely on the use of 10m–cla ...
First Results from the WISE Enhanced Resolution Galaxy Atlas
... dow of the electromagnetic spectrum, from the radio to the X-ray, provides a complementary set of tools that, in combination, reveal the internal life cycle of galaxies. The infrared window, for example, has dual capability: sensitive to stellar light from the evolved population of stars and relativ ...
... dow of the electromagnetic spectrum, from the radio to the X-ray, provides a complementary set of tools that, in combination, reveal the internal life cycle of galaxies. The infrared window, for example, has dual capability: sensitive to stellar light from the evolved population of stars and relativ ...
astro-ph/9808039 PDF
... blue and Hα images are on the right. Both the FUV and the optical bands show bright knot complexes against a relatively faint, but still evident, background. However, the morphology of the background depends on whether it is observed in broad-band continuum or in line emission. In the Hα image, the ...
... blue and Hα images are on the right. Both the FUV and the optical bands show bright knot complexes against a relatively faint, but still evident, background. However, the morphology of the background depends on whether it is observed in broad-band continuum or in line emission. In the Hα image, the ...
Cool Subdwarf Investigations (CSI) I: New Thoughts for the Spectral
... 1997 confirmed that all are M subdwarfs). Although they were termed subdwarfs, he used the same spectral classification as dwarfs (M0 and M2, see Kuiper 1940 Table 1). The “sd” spectral classification prefix for subdwarfs did not appear until Joy (1947), when he used the strengthening of the Lindbla ...
... 1997 confirmed that all are M subdwarfs). Although they were termed subdwarfs, he used the same spectral classification as dwarfs (M0 and M2, see Kuiper 1940 Table 1). The “sd” spectral classification prefix for subdwarfs did not appear until Joy (1947), when he used the strengthening of the Lindbla ...
Study properties of dwarf galaxies in and around the nearby Lynx
... The galaxy evolution versus the global environment (clusters, groups, voids) is a long-studied problem. Voids are delineated by luminous (L > L*) massive objects and populated by dwarfs. The galaxy densities and other parameters vary significantly from one void to another. One expects that not only ...
... The galaxy evolution versus the global environment (clusters, groups, voids) is a long-studied problem. Voids are delineated by luminous (L > L*) massive objects and populated by dwarfs. The galaxy densities and other parameters vary significantly from one void to another. One expects that not only ...
Chapter 17 - Astronomy
... hot gas. Such halos around spiral galaxies have been observed. 2. The presence of gas in spiral galaxies dampens out the disruptive effects of mergers, allowing spirals to survive a violent collision. 3. Over its lifetime, a spiral can make many transitions between being barred or unbarred. 4. As a ...
... hot gas. Such halos around spiral galaxies have been observed. 2. The presence of gas in spiral galaxies dampens out the disruptive effects of mergers, allowing spirals to survive a violent collision. 3. Over its lifetime, a spiral can make many transitions between being barred or unbarred. 4. As a ...
CENTRAL STARS OF PLANETARY NEBULAE IN THE LARGE
... values. In addition, the lower metallicity of the LMC relative to the Milky Way allows the role of metallicity in low/intermediate–mass stellar evolution to be assessed. The largest impact a higher metallicity is expected to have on a star’s evolution is a more efficient radiative driving during its ...
... values. In addition, the lower metallicity of the LMC relative to the Milky Way allows the role of metallicity in low/intermediate–mass stellar evolution to be assessed. The largest impact a higher metallicity is expected to have on a star’s evolution is a more efficient radiative driving during its ...
Core formation in giant planets formed through
... more quickly. This leads to a fragmentation of the cloud. Each fragment nally forms its own star. During the collapse, the gravitational binding energy is converted into thermal energy. First the cloud is optically thin, this means that the thermal radiation of the nebula can escape from the gas. I ...
... more quickly. This leads to a fragmentation of the cloud. Each fragment nally forms its own star. During the collapse, the gravitational binding energy is converted into thermal energy. First the cloud is optically thin, this means that the thermal radiation of the nebula can escape from the gas. I ...
The UKIRT Infrared Deep Sky Survey ZY JHK Photometric System
... Key science goals of UKIDSS include a census of very low temperature brown dwarfs (Section 5.2.2) and the identification of quasars with redshifts beyond the current maximum reached by SDSS, z = 6.4 (Section 5.4). To enable such goals, a novel feature of UKIDSS is the extension of imaging observatio ...
... Key science goals of UKIDSS include a census of very low temperature brown dwarfs (Section 5.2.2) and the identification of quasars with redshifts beyond the current maximum reached by SDSS, z = 6.4 (Section 5.4). To enable such goals, a novel feature of UKIDSS is the extension of imaging observatio ...
Book Describing Techniques to Detect Transiting ExoPlanets
... How things change! We now know that planets are everywhere in the galaxy. Billions upon billions of planets must exist! This is the message from the tally of ~ 400 extra-solar planetary systems (as of mid-2009). Among them are 60 exoplanets that transit in front of their star (46 that are brighter t ...
... How things change! We now know that planets are everywhere in the galaxy. Billions upon billions of planets must exist! This is the message from the tally of ~ 400 extra-solar planetary systems (as of mid-2009). Among them are 60 exoplanets that transit in front of their star (46 that are brighter t ...
PDF hosted at the Radboud Repository of the Radboud University
... Despite the importance of type Ia supernovae for stellar astrophysics, galactic evolution and cosmology, the nature of the progenitor systems giving rise to these events remains mysterious, and no direct, unambiguous detection of a type Ia supernova progenitor has been made at the time of the writin ...
... Despite the importance of type Ia supernovae for stellar astrophysics, galactic evolution and cosmology, the nature of the progenitor systems giving rise to these events remains mysterious, and no direct, unambiguous detection of a type Ia supernova progenitor has been made at the time of the writin ...
Physics of Neutron Star Crusts - Institut d`Astronomie et d
... stars is assumed to be in complete thermodynamical equilibrium with respect to all interactions at zero temperature and is therefore supposed to be in its ground state with the lowest possible energy. The validity of this assumption is discussed in Section 3.4. The ground state structure of neutron ...
... stars is assumed to be in complete thermodynamical equilibrium with respect to all interactions at zero temperature and is therefore supposed to be in its ground state with the lowest possible energy. The validity of this assumption is discussed in Section 3.4. The ground state structure of neutron ...
Population effects on the red giant clump absolute magnitude, and
... dSph, and further comment on their reliability. The largest DM RC values are found for the I Magellanic Clouds and Carina dSph, which turn out to be located at distance moduli ,0:2±0:3 mag longer than indicated by works which ignore population effects. The Galactic w ...
... dSph, and further comment on their reliability. The largest DM RC values are found for the I Magellanic Clouds and Carina dSph, which turn out to be located at distance moduli ,0:2±0:3 mag longer than indicated by works which ignore population effects. The Galactic w ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.